MiR-210 is induced by Oct-2, regulates B-cells and inhibits autoantibody production. Mus musculus

MicroRNAs are small, non-coding RNAs that regulate gene expression post-transcriptionally. Here, we show that miR-210 is induced by Oct-2, a key transcriptional mediator of B-cell activation. Germline deletion of miR-210 results in the development of autoantibodies from 5 months of age. Overexpression of miR-210 in vivo resulted in cell autonomous expansion of the B1 lineage and impaired fitness of B2 cells. Mice over-expressing miR-210 exhibited impaired class-switched antibody responses, a finding confirmed in wild-type B-cells transfected with a miR-210 mimic. In vitro studies demonstrated a defect in cellular proliferation and cell-cycle entry, which was consistent with the transcriptomic analysis demonstrating down-regulation of genes involved in cellular proliferation and B cell activation. These findings indicate that Oct-2 induction of miR-210 provides a novel inhibitory mechanism for the control of B cells and autoantibody production. Overall design: Splenic B-cells from different mouse strains were stimulated with either anti-IgM, CD40L and IL-4 or LPS for 48 hours Treatments: rest (unstimulated), Fab/Fab2 (=anti-IgM + CD40L + IL-4), LPS. There is no difference between Fab and Fab2 stimulation conditions. The goal of this study was to look for activation-induced microRNA changes upon B-cell activation, of which miR-210 was one of them.